Tristiropsis acutangula Radlk.

Tree, up to 35(-53) m, dbh up to at least 6 cm, often with buttresses up to 3 m high, 4 m wide, and 3 cm thick. Branchlets 4-10 mm thick, fulvous-tomentose, glabrescent and then shiny purple-brown, older parts more or less pustular lenti-cellate. Leaves up to 2 m long; petiole up to 20 cm long or more and up to 1.5 cm thick, rachis terete, the ultimate parts flattened to flat above; petiolules 1-8 mm long, above with a broad and flat groove, slightly pulvinate. Leaflets ovate to elliptic, 5-18 by 1.5-8 cm, index 2-4, glabrous (or bearded in the nerve-axils beneath); base acute to obtuse (or truncate); margin entire to subundulate; apex (emar-ginate to) obtuse (to acute), often mucronulate; midrib above slightly sunken, broad, nerves 0.75-1.5 cm apart, nearly straight to slightly curved, all looped and joined near the margin, faint; intersecondary nerves well developed, often joined with the marginal arches. Thyrses up to 40 cm long, densely, appressedly, shortly, brownish hairy; peduncle up to 15 cm long; stalks to cymes up to 8 mm long; pedicels slender, 3-10 mm long. Sepals cream to greenish, persistent and black in fruit, outer 2 elliptic-ovate to orbicular, c. 3 by 2.5 mm; inner ± obovate, c. 4 by 3 mm, margin petaloid, crenulate at apex, with a few hairs inside. Petals cuneate at base, broad-elliptic to broad-ovate, 2.5-3.5 b) 2.2-2.5 mm, creamy-white, margin below the insertion of the scale long-ciliate, furthermore sparsely ciliate, apex crenulate, inside glabrous; scale about 0.5-0.6th the length of the petal, divided till the base, woolly on the inner surface. Disc divided into a thick, spreading outer and a thin, erect inner wall, black, glabrous or the latter ciliate. Stamens: filaments c. 3 mm long, patent-hairy at least in the upper 0.6th part; anther c. 1.5 mm long, densely hairy on the dorsal side of the connective, sometimes also on the ventral side. Pistil: ovary c. 3 mm long; style slightly curved, c. 2 mm long. Fruits ellipsoid to subglobular, widest about or above the middle, narrowed to short-stipitate at base, 3-4-angular to 3-4-ribbed in cross section, 20-30 by 14-25 mm, yellowish green to dark-yellow when ripe, patently short-hairy inside, often sterile but well developed.

On Christmas Island occurs on the plateau in primary forest where it forms about 6 % of the canopy. Less frequent on the terraces, but is a major emergent species in the marginal forest. Tolerant of limestone soils.

Uses The wood is said to be hard, heavy, and durable, and is used as a timber. For a description of the timber, see p. 427.